Muffler discoloration

GoldenMotor.com

FlyingHorse87

New Member
Jun 27, 2010
24
0
0
Jeannette, PA
I'm breaking in my engine and the chrome muffler is discoloring or "blueing". I know from motorcycling that exhaust blueing means the engine is running too rich, but is it running rich from the 16:1 petrol/oil mix or does the carb need adjusting? My idle screw is about 4 turns out, the side is about 1/8" from the bottom of the carb body. Could it just be the cheap chrome plating burning off?
 

nidyanazo

New Member
May 25, 2010
316
1
0
SoCal
The change in color is normal.
To see if it's running rich, do a plug chop.
That's where you run the bike at full throttle (or part throttle, whatever rpm range you want to check) and then kill the motor.
Pull the plug and check if it's dark and wet (rich), white and burnt (lean), or just right with a nice brown tint/
 
Last edited:

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
If you are talking about a China 2 smoke? That screw on the side is for idle adjustment. It will not change you air to fuel. You can move the clip up and down on the needle valve.
 
Last edited:

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
The change in color is normal.
To see if it's running rich, do a plug chop.
That's where you run the bike at full throttle (or part throttle, whatever rpm range you want to check) and then kill the motor.
Pull the plug and check if it's dark and wet (rich), white and burnt (lean), or just right with a nice brown tint/

Good advice - 'cep ya wanna let the motor cool down before trying to remove the spark plug as you may pull the threads out of a hot motor ;)
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
1,797
113
Los Angeles, CA.
Use 24:1 for the break in!! 16:1 is too much oil!
& "yes", 16:1 will cause it to run leaner.. More oil = less gas in every drop that goes through the carb & into the engine! ;)
 

Kevlarr

New Member
Jul 22, 2009
1,628
4
0
Mi
When I took my muffler apart I noticed that the area that turns blue is just past where the catalytic converter is so I'm thinking it more the heat from that then anything.
 

kicking

New Member
Apr 11, 2010
403
0
0
mississippi
When I took my muffler apart I noticed that the area that turns blue is just past where the catalytic converter is so I'm thinking it more the heat from that then anything.
yep its more than likely from heat ,,, thats why if I paint mine it will be ,,, im thinking about white ,,,it has got to be muffler paint though to stand up to the heat ,, i painted the manifold and tail pipe on my van with some i bought from carquest because of rust,,,, looks good!
 

FlyingHorse87

New Member
Jun 27, 2010
24
0
0
Jeannette, PA
Use 24:1 for the break in!! 16:1 is too much oil!
& "yes", 16:1 will cause it to run leaner.. More oil = less gas in every drop that goes through the carb & into the engine! ;)
Yes, I need to cut the mixture back. The instructions stated to run 16:1 for the first two tanks! That seemed like way too much oil, it drips and smokes like crazy.